Improved process of reducing wood and woody fibres for paper-pulp



diluted States tenant can.

Letters Patent N 96,239, dated October 26, 1869; a'ntedaterl October 20, 1869.

IMPROVED PROCESS or REDUCING- woo'n AND WOODY means FOR PAPER-PULP.

The Schedule referred to in these Letters Patent and making part of the same.

To all whom it may concern:

Be it known thatl, VINCENT E. KEEG-AN,1V[. D., of *Koston lziighlands, in the county ofSufiolk, in the State of Massachusetts, have invented a new and improved Process for Reducing Wood and Woody Fibres; and, I do hereby declare that the following is a. full and exact description thereof.

The nature of my invention consists in a peculiar inanncroi' reducing wood and woody fibres-with alkalies, whereby I produce an immediate and complete action,

To enable others skilled in the art to use my in.-

' veutiou, I will proceed to describe the process.

I first reduce the wood to blocks, chips, or crushed shreds of about one-half an inch in thickness, and' three or four inches long, whichis a very practical size. Larger pieces may he used, even boards, provided that they are all bf the same size, nearly. I then boil these chips in a caustic alkaline solution of about 2.5 gravity, although a weaker or stronger solution may be used, according to the time that may be desired to reduce them in. Having boiled them for about thirty minutes briskly, and if they are completely saturated, I drain off the supernatantliquor, and place the saturated chips into a boiler, that must then be made steam-tight, pertcctlyso, and to'revolve upon its horizontal arms, (to prevent the liquor pressed out oi the chips by the stomp-pressure from settliug,) in a chamber heated to 325, and in two hours the reduction will be completed. Some arrangement will be required on the boiler to enable the operator to test the condition of the contents, so that the exact time will be known when the chips are done, and I propose the construction of a valve upon the inside of the boiler, to act automatically, and connected with acyliiuler-piston on the outside, provided with a cup on the end that reaches the boiler; then, by forcing this piston into the boiler through the valve-opening,-and dipping out with the cup a few of the chips, their condi tion can be tested, and a-t't-eranumber of practical operations, the strength of the alkali used, degree of heat, time by testing, &-o., being all noted, then the further use of the test cylinder-piston will be unnecessary.

When the chips are so reduced that they make a perfect oottony pulp by adding a little water,-they must be taken out of the boiler, and washed thoroughly from the alkali'by boiling in water, and then washed pure and quitewhite with hot steam, in such a manner that great suction will be produced in a mass of the pulp, so that the coloring-matter contained in the tubes of the fibres will be drawn out, leaving thenr almost pure white, and requiring but asmall amount of bleaching-agent to bleach them afterward.

I now, previous to bleaching the pulp, boil it for one quarterv of an hour in water acidulatcd with hydrochlozic acid, using one pound of acid to four gallons of water, and then strain it, and nowbleach it by any process; but to use first, chlorine-gas, and then chloride of lime, will be found most economical. Itcan then be made into paper of the nicest quality.

I prefer the soft woods to the hard woods, for their fibremakes a superior paper to any other.

\Vlrat I claim, and desire'to secure by Letters Patent, is-

The process for reducing wood and woody fibres, for the manufaotme of paper-pulp, wit-h alkalics, in the manner of the process as described, or its substantial equivalent.

VINCENT E. KEEGAN, M. D.

Witnesses:

Anna T. Knnoas, H. P. Knncsx. 

